Army of the Mississippi

The Army of the Mississippi was a Union army that was active from 23 February to October 1862 and briefly in 1863 during the American Civil War. John Pope was the army's first commander, and it had five divisions. The army fought at Island Number Ten, Corinth, and Iuka, but the army was divided into the XIII Corps and XIV Corps in October 1862 after Pope took command of the Army of Virginia and the new commander William S. Rosecrans took over the Army of the Ohio. In 1863, the army was briefly revived by John A. McClernand for his capture of Arkansas Post in January 1863, only for the army's two corps to be returned to the Army of the Tennessee on 12 January.